After replacing rear brake pads Airmatic system is not working. Compressor does not run and rear bags are deflated. Checked the Fuses all good, bench tested compressor relay and pressure relief valve it checks good, Checked wiring and connectors near compressor and Pressure relief valve all are ok and no rubs or broken wires. No Air leaks. I also did not have any messages on dash till I drove the car a short distance at slow speed. Now shows " Suspension Failure" message. I also Manually triggered the relay and the Compressor does run but rear bags still do not fill. I'm Guessing the computer is not sending the signal to the relay to run and most likely in a fail safe mode or locked out from the computer side. Anyone have any Ideas before I have to spend the outrageous fee to have it hooked to a scanner?? All was working good till I lifted car not sure what could have changed.

 

Airmatic uses sensors to determine the relative height of the car. By any chance, the sensors got damaged, bent somewhere when the car was lifted? Perhaps the sensors are sending the "correct height" signal to the module; therefore, no need to activate the compressor.

If you get a MB specific scanner, it should show you the height reported by the sensor. If the height is implausible based on physical evidence, and both incorrect, it is likely something got disconnected or bent in the rear.